Nonferrous alloy



Patented Dec. 1, 1953 Nii'niawnig? efiisfliiiationrgb ary25f 1950;"sesame. 146,387

9 Claims.

This invention relates" to' alloys nickel,- chro'm'ium, manganese *and'-mo1ybdenur n,--- and particularly to suehalloysdn which the nickel Fand. chromium contents predominatei-- x object of the in-ventibn istoproi ide -such a stainlessnon-ferrous alloy characteri'zied by hightensile strength;- and resistance to corrosive' at tack' by suchsubstances as acid, alkali; sea water'- andfcorrosive-gasesi A relatedobject is-to pro vide such an alloy which *is "highly-Iresistant to fwear. Othen object's are to wane an alloy capable of high surface polishand 'hi'gh ele'ctrical resistivity;- v I There have heretofore been'piopose'dnon-fer rous alloys composed principally of nickel: andchromium and there have ever been proposed nickeLchromium alloys"containing molybdenum.

None of these 'non-ferrous'alloys,however, have been 'characterizedby-exceptionally high tensile" strength, for example; beyond 95,000 lbs.per" squareinch. In accordancewith my invention, I can provide an alloyca ipa ble-"of' a tensile strength in the order of 150,000 lbs. persquare inch; andI havebeen able "to do thisby my dis covery that" theaddition to" a nickel-chromium" alloy of both manganese and molybdenumin proper proportions can" markedly increase the tensile "strerig'thf asf wel'l as the 'Wear resis'tancei Without undue brittleness;

While molybdenumand mangansehave ih ere tofore' been used separatelyfto1 some extent in arly rerr'o' s meta "alloys; for one purposeor another,the use ofboth' molyb- Ea 'num fandj" manganese in a nickel-chromium"metal alloys" particul base alloy has never heretofore been us'edin'pro-- portions which make them'asignific'ant part'of' the completedalloyg" In the 'courseof my"'ex perim'ents I have found'thatthe"additiori of molybdenum or of manganese "separately froni eachother in a nickel-chrorhium alloy does not increase the tensile strengthappreciably beyond 95,000 1bs.'pe'r square inch, regardless" of amountsused. However, whenI addedboth"molyb'denum and manganese in' properproportions? to the nickel-chromium alloys, I exp'eriencedfthe 'un;usual result that the tensile strengthbould there by bea1mo'st-doubled.- The-fpresenceof man-'- ganese in the proportionofaboutz'td "4% by weight of the alloy'and ofmolybdenum in-theproportionof about /;*to 2% by weig1it of the alloy, can 1 increase theI tensile strength 'of a nickel chror'nium' alloy-fromabout 79,700'toabout- The inclusion of the maaeariese beriefits the; alloyb3zincreasing its malleability andtoughness as" well as providing the-'eittr'aordinari-ly high tefis'ile 'stien gth in cornbir1alti'ori-tviththe melyb deriuiri. The molybdenum 'inaddition' to produe ing,'th'e great-tensile strength i in" company -with' th'e'manganese?'providesfor the allby th dsir; able properties of increased"ductility and'fatig'ue" resistance.

Increasingeither the manganese or the mo1yb=' denumvor both,substantially above %*or -2%;" would create an alloy ofunduerespectively, brittleness; and decreasing the manganese" ormolybdenum, or both, substantially below 2% and respectively,wouldniarkedly "decreasfihe tensil''strengthI I have found thatmany-'other desirable characteristics can be introduced or improved inmy novel alloyrby theaddition of proper amount's of" other substanceswithout seriously-impai'ri'rig the-- extremely high tensile strength. 20

the-characteristic of the nickel-chromium-mangan'senolybdenurri" mamentioned above; I have found,"forbiamplefthat 'by' adding from about 2to 4% by Weightbfsilver to the alloy, the resistance to corrosion by seaWater, and also the malleability. of the alloy, can be markedly "increased. Substantially. less than silver"fai1s* to -afiord very. greatcorrosion resistance; and" any substantial excess beyond 4%silverdoe'snot go into solution, and will merely remain present assilver inclusions in thealloy. In many cases, anf'ex'de'ss of as much asabout 2% of silver (that is','a-tota1"si'1ver content-of about'6%) 'canbeftol erated without"serious adverseeffe'ct use wane inclusions?Another substance "which" it is very" desirable to use whenmaking thealloy, isboron; which' 'is desirable for its highly deoxidiz'ing"properties;

and this is preferably used in the'form'boronic copper. The 'grade'knowncomm'ercially as No;

4: boronic 'eopper F3 /2 is preferred and its presencecontributes=considerably. to" the: corrosion resistance.

A-furthe'r especially desirable additionis a small amount ofaluminumy-for example, in theorder of"1%* by Weight ofthe alloyjwhich'it is desired to add'to the molteri mixture for itsdgas'ify'in'gproperties, as well as for'its" attribute of increas:

ingf the corrosion resistance of the finished-alloy to acids." While thealuminum 'may possibly be dispensed with i n semecasee its omission willincreasethe risk 0: gas pocket and -b1owh'ole' formatiofl in the alloy;and there will seldom'if ever bear iy "reas'on ior omitting thealuminum.

Such additives" are referred to herein as being not sub'vers'ive offectively. It goes off as a gas during th melting, carrying other gasesoff with it. Actually the amount of the aluminum can be increased evenbeyond 4% without harmful result, but there would be no advantage indoing it, as it would simply increase gas evolution beyond any usefulamount. In using up to about 1% aluminum, nearly all of it goes off asgas. Using substantially more than 1% aluminum will leave some aluminumin the alloy, which may have beneficial effect in increasing corrosionresistance.

While the proportions of the various ingredients set forth above shouldbe maintained within the proper limits to provide a suitable alloy, itshould be recognized that more or less variation in the relativeproportions is permissible, and even desirable for bringing out specialproperties in the finished product, for particular purposes, as will bemore fully set forth hereinbelow.

I have discovered that the proportions of the ingredients may range asfollows. Considering an alloy containing only nickel, chromium,manganese and molybdenum, these may range in the following relativeproportions, in which the percentages are given by weight, based on thetotal weight of these four ingredients:

Percent Nickel 69 to 80 Chromium 16 to 25 Manganese 2 to 4 Molybdenum A2to 2 The following is a typical example of an alloy compositionconsisting of these four ingredients:

Example I Percent Nickel '74 Chromium 23 Manganese 2 /2 Molybdenum /2The following two examples show specific variations within thepermissible range:

In all these examples, the percentages are given by weight, based on thetotal weight of the named ingredients. In Example II, the alloy will bemore ductile with good fatigue resistance due to the molybdenum contenthaving been increased 1%; the 2% of manganese was found to lower themalleability. In Example III, the alloy will be more malleable andtough, due to the manganese content having been increased by 1 /2%. The1 /2% increase in molybdenum was found to give higher fatigueresistance, ductility and strength, than in Example I.

As has already been explained, it is preferable to add a small amount ofboron, preferably in the form of boronic copper, and also a small amountof aluminum. The addition of aluminum should be in the order of about 1%by weight; and this addition can be made in any of the foregoing threeexamples, simply by adding in the alloys of these examples an amount ofaluminum equal to about one percent by weight, considering the boronicsubstance, if any, to be present in an amount stated below, and thenickel, chromium, molybdenum and manganese to add up to the balance inthe relative proportions given in the above-mentioned range or examples.The aluminum may be added to produce its advanta e regardless of whetherthe boron or boron compound is present.

When the boron compound is added, as will ordinarily be preferred, thiscan be added in the form of boronic copper in the order of about 2% byweight, considering the aluminum, if any, to be about 1% by weight, andthe nickel, chromium, molybdenum and manganese to add up to the balance,in the relative proportions given in the above-mentioned range orexamples.

It is possible to use boron in free form instead of in the form ofboronic copper, but the use of free boron will usually be less desirablethan the boronic copper because of greater violence of action, and itstendency to produce a glassy hardness of the alloy.

Boronic copper is a well known commodity; it is ordinarily a purecopper, such as electrolytic copper, impregnated with boronic gases.Grade No. 3 Boronic Copper Alloy, which is the preferred grade, is acommercial product. There are several grades of boronic copper, whichdiffer somewhat from each other in the proportion of boron in thecopper.

Four boronic-copper alloys were experimented with to determine therelative effectiveness of the several grades; and for this purposeboroniccopper alloys designated as grades #2, #3, #4, F3 /2 and #5 Swere used. In this system of grading, the proportion of boron relativeto the copper in the alloy increases with the higher numbers. Thus, the#1 grade has the least boron, and the #5 S grade has the most boron.

It was found that when using the #2 grade, there resulted in thefinished metal, a considerable number of blow holes and gas pockets, andthe fluxing was not as good as in the higher numbered grades, With theuse of the #3 grade, boronic-copper alloy, excellent fiuxing wasexperienced and there were no blow holes or gas pockets in the finishedproduct. When using the #4 boronic copper F3 /z, there was experiencedgood fluxing and freedom from blow holes and gas pockets; although inthis case, the tensile strength of the finished metal was slightly lowerthan when using the #3 grade boronic copper. When using the #5boronic-copper alloy S,

there was freedom from blow holes and gas pockets, but considerably morebrittleness was present in the finished metal. From this work, itfollows that the intermediate grades, #3 and #4 FB /2 will ordinarily bepreferred, with the #3 grade having the preference.

As noted above, the addition of silver as an additive will increase thecorrosion resistance and the malleability; and the addition of silvermay be in an amount of about 2 to 4% by weight based on the weight ofthe alloys set up in Examples I, II and III. A particularly good amountof silver for a good malleable alloy is about 3% by weight of the alloy,considering the boronic substance and/or aluminum, if any, to be presentin amounts stated above, and the nickel, chromium, molybdenum andmanganese to add up to the balance in the relative proportions stated inthe above range or examples. When the alloy is composed of all thesesubstances, examples of suit Aluminum able relative proportions are asfollows; the parts being by weight:

3 Example 1 Example Exam 1e IV -=V VI Percent 5 Percent j Ferment -7l 7069 19y- 23 1i 2 1 Silver 2 2 2, 4 4 Boronic copper (Grade No. 4,

33%) 3 1 2% Molybdenum 1% 2 Aluminum 2 3 1 1% "The following is atypical example of a relatively soft alloy which I can make according to.my invention:

Example VI I Percent 72 Shot form. 18 Metallic, pea size.

Powderiorin.

Shot form.

Shot for-m.

Powder form.

Tlfiin strips cut up to bits, or shot orm.

Boro-nic copper. Molybdenum S o r v-news:

In all vof the foregoing examples, the nickel, silver and boronic coppermay be introduced into the crucible or furnace in shot form; thechromium may be in pea size metallic form; the manganese and molybdenummay be used in powder form and the aluminum may be in the form of thinout up strips or pieces.

The alloy can be made in accordance with the following procedure. I usea furnace, preferably an induction furnace, capable of being raised to atemperature of at least 3000 F.; and I first bring the furnace to atemperature of about 2000 F. I then place in ;the furnace .a cruciblecontaining all of the nickel, chromium and molybdenum which is to beused, and also onehalf of all the boronic copper, when boronic copper isused. I have found that this preheating of the furnace to about 2000 F.before placing in it the crucible containing the ingredients will avoidthe low oxidizing temperatures of nickel.

manganese will be added, the mass being again stirred upon thisaddition.

Where aluminum is used, as is ordinarily preferable to prevent theformation of gas pockets and blow holes in the product, this will beadded after the temperature has been maintained for a few minutes atabout 2800" F., after the addition of the manganese; and the aluminumwill similarly be thoroughly stirred into the liquid mass. After thealuminum has been completely added, the temperature will be allowed todecrease to about 2700 R, whereupon the liquid mass will be poured intomolds which have been heated to about 600 F.; and the molds containingthe alloy will then be allowed to cool down to room temperature. Suchmolds can be made of a suitable substance such as cast iron or graphite.

It will be recognized that by my invention, 1 have provided an unusuallystrong non-ferrous alloy, which by proper use or non-use of theadditives can be made soft or ductile, as desired, or on the other hand,can be made relatively hard. Furthermore, the alloy is resistant to acidand corrosion. Moreover, by proper variation of the proportions of theingredients, it is possible to produce alloys of different grades ofhardness, electrical conductivity and ductility. The softer grades ofthe alloy can be rolled into flats, or other desired shapes, or can bedrawn into wire. Furthermore, the alloy can be soft soldered, brasssoldered, gold soldered and electrically welded.

I claim:

1. A stainless non-ferrous alloy having the characteristics of highertensile strength than nickel-chromium alloys and .of resistance tocorrosion to acid, alkali, sea Water and corrosive gases, said alloyconsisting of nickel, chromium, manganese and molybdenum in theapproximate proportions of 69% to by weight of nickel, 16% to 25% byweight of chromium, 2% to 4% by weight of manganese and about to "2% byweight of molybdenum, based on the total weight of the nickel, chromium,manganese .and molybdenum in the alloy, and free of material subversiveof said characteristics.

2. A non-ferrous alloy having the characteristics of higher tensilestrength than nickel,- chromium alloys and of resistance to corrosion toacid, alkali, sea water and corrosive gases, said alloy consisting ofnickel, chromium, manganese, molybdenum, and silver, the nickel beingpresent in an amount of 69% to 80% by weight, the chromium being presentin an amount of about 16% to 25% by weight, the

manganese being present in an amount of about 2% to 4% by weight, andthe molybdenum being present in amount of about 1 to 2% by weight, basedon the total weight of the nickel, chromium, manganese and molybdenum inthe alloy, and the silver being present in an amount of about 2% to 6%by weight, based on the total weight ofthe nickel, chromium, manganese,molybdenum and silver.

3. A non-ferrous alloy having the characteristics of higher tensilestrength than nickelchromium alloys and of resistance to corrosion toacid, alkali, sea water and corrosive gases, said alloy consisting ofnickel, chromium, manganese, molybdenum, and aluminum, the nickel beingpresent in an amount of 69% to 80% by weight, the chromium being presentin an amount of about 16% to 25% by weight, the manganese being presentin an amount of about 2% to 4% by weight, and the molybdenum beingpresent in an amount of about to 2% by weight, based on the total weightof the nickel, chromium, manganese and molybdenum in the alloy, and thealuminum being present in an amount of approximately 1% by weight basedon the total weight of the nickel, chromium, manganese, molybdenum andalumimun.

4. A non-ferrous alloy having the characteristics of higher tensilestrength than nickelchromium alloys and of resistance to corrosion toacid, alkali, sea water and corrosive gases, said alloy consisting ofnickel, chromium, manganese and molybdenum in the approximateproportions of 69% to 80% by weight of nickel, 16% to 25% by weight ofchromium, 2% to 4% by weight of manganese and about /2% to 2% by weightof molybdenum, based on the total a minor but significant amount ofboron, and ,free of material subversive of said characteristics.

5. A non-ferrous alloy having the characteristics of higher tensilestrength than nickelchromium alloys and of resistance to corrosion toacid, alkali, sea water and corrosive gases, said alloy consisting ofnickel, chromium, manganese, molybdenum, silver and boron, the nickel,chromium, manganese and molybdenum being in the approximate relativeproportion of 69% to 80% by weight of nickel, 16% to 25% by weight ofchromium, 2% to 4% by weight of manganese, to 2% by weight ofmolybdenum, and the silver being present in an amount of about 2% to 6%by Weight of the total alloy and the boron being present in a minor butsignificant amount.

6. A non-ferrous alloy having the characteristics of higher tensilestrength than nickelchromium alloys and of resistance to corrosion toacid, alkali, sea water and corrosive gases, said alloy consisting of,by weight, about 70% nickel, about 29% chromium, about 2% manganese,about 2 /2% silver, about 1 /2% molybdenum and about 3% aluminum, andsuch re mainder as may exist being not subversive of saidcharacteristics.

7. A non-ferrous nickel-chromium-manganesemolybdenum metal alloy havingthe characteristics of higher tensile strength than nickelchromium alloyand being resistant to corrosion by acid, alkali, sea water andcorrosive gases, said alloy consisting of nickel in amounts ranging fromabout 69% to 80% by Weight, chromium in amounts ranging from about 16%to 25% by weight, manganese in amounts ranging from about 2% to 4% byweight, and molybdenum in amounts ranging from about to 2% by weight,based on the total weight of the nickelchromium-manganese and molybdenumin the alloy, such remainder as may exist being not subversive of thesaid characteristics.

8. A corrosion-resistant, non-ferrousnickelchromium-manganese-molybdenum metal alloy having thecharacteristics of higher tensile strength than a nickel-chromium alloy,and of being resistant to corrosion by acid, alkali, sea water andcorrosive gases, said alloy consisting of nickel in amounts ranging fromabout 69% to by weight, chromium in amounts ranging from about 16% to25% by weight, manganese in amounts ranging from about 2% to 4% byweight, and molybdenum in amounts ranging from about /2% to 2% byweight, based on the total weight of the nickel-chromium-manganese andmolybdenum in the alloy, the remainder being material not subversive ofthe said characteristics, including silver in an amount of about 2% to6% by weight, based on the total weight of the nickel, chromium,manganese, molybdenum and silver.

9. Anon-ferrous nickel-chromium-manganesemolybdenum metal alloy havingthe characteristics of higher tensile strength than a nickelchromiumalloy and of being resistant to corrosion by acid, alkali, sea water andcorrosive gases, said alloy consisting of nickel in amounts ranging fromabout 69% to 80% by weight, chromium in amounts ranging from about 16%to 25% by weight, manganese in amounts ranging from about 2% to 4% byweight, and molybdenum in amounts ranging from about to 2% by weight,based on the total weight of the nickelchromium-manganese and molybdenumin the alloy, the remainder being material not subversive of the saidcharacteristics, including boron in a minor but significant amount MAXGORSCHALKI.

litoferenccs Cited in the file or" this patent UNITED STATES PATENTSNumber Name Date 1,115,239 Parr Oct. 27, 1914 1,489,166 Chevenard Apr.1, 1924 1,572,996 Girin Feb. 16, 1926 2,480,432 Allen Aug. 30, 1949FOREIGN PATENTS Number Country Date 26,940 Great Britain 1907 354,765Great Britain Aug. 12, 1931

1. A STAINLESS NON-FERROUS ALLOY HAVING THE CHARACTERISTICS OF HIGHERTENSILE STRENGTH THAN NICKEL-CHROMIUM ALLOYS AND OF RESISTANCE TOCORROSION TO ACID, ALKALI, SEA WATER AND CORROSIVE GASES, SAID ALLOYCONSISTING OF NICKEL, CHROMIUM, MANAGANESE AND MOLYBDENUM IN THEAPPROXIMATE PROPORTIONS OF 69% BY WEIGHT OF NICKEL, 16% TO 25% BY WEIGHTOF CHROMIUM, 2% TO 4% BY WEIGHT OF MANGANESE AND ABOUT 1/2% BY TO 2% BYWEIGHT OF MOLYBDENUM, BASED ON THE TOTAL WEIGHT OF THE NICKEL, CHROMIUM,MANGANESE AND MOLYBDENUM IN THE ALLOY, AND FREE OF MATERIAL SUBVERSIVEOF SAID CHARACTERISTICS.